light mediated photocatalyst free C–S cross-coupling reaction has been developed for the synthesis of thiochromane derivatives through photoinduced electron transfer (PET). This methodology was further utilized for the synthesis of thiochroman-4-ol through intermolecular three-component cross-coupling reaction. The reaction proceeds via C–Sbondformationthrough EDA complex/thioester cleavage/inter-or
Enantioselective Intramolecular Reductive Heck Reaction with a Palladium/Monodentate Phosphoramidite Catalyst
作者:Subramaniyan Mannathan、Saeed Raoufmoghaddam、Joost N. H. Reek、Johannes G. de Vries、Adriaan J. Minnaard
DOI:10.1002/cctc.201601153
日期:2017.2.21
A palladium‐catalyzed enantioselective reductive Heckreaction of enones using monodentate phosphoramidite ligands is described. α,α,α’,α’‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol (TADDOL)‐based phosphoramidites with palladium(II) acetate, and N‐methyl dicyclohexylamine as reducing agent gives the reductive Heck product in high yields and enantioselectivities of up to 90 %. The solvent plays an important
An efficient diastereoselective synthesis of α-tetralone-fused spirooxindoles is reported. The Pd-catalyzed domino reaction proceeds through a carbene migratoryinsertion followed by a 6-endo-trig mode of conjugate addition sequence from easily accessible isatin-derived N-tosylhydrazones and 2′-iodochalcones. The versatility of the protocol has been showcased by high functional group tolerance, broad
Organocatalytic cascade reactions for multi-functionalized chiral cyclic ethers through vinylidene <i>ortho</i>-quinone methides
作者:Shiqi Jia、Yu Chang、Yuhong Tian、Hui Mao、Wenling Qin、Pengfei Wang、Hailong Yan
DOI:10.1039/d1cc05340j
日期:——
An organocatalytic approach to installing various alcohols into the carbonyl of α,β-unsaturated ketones mediated by VQM intermediates was achieved, followed by dearomatization to provide the stereo-defined cyclic ethers via a cascade process. Along with the transformations, this strategy affords efficient access to the underexplored chiral cyclic ether chemospace.
Copper-Catalyzed One-Pot Synthesis of 2-Arylthiochromenones: An in Situ Recycle of Waste Byproduct as Useful Reagent
作者:Subramani Sangeetha、Govindasamy Sekar
DOI:10.1021/acs.orglett.8b03508
日期:2019.1.4
Copper-catalyzed one-pot synthesis of various 2-arylthiochromenones is developed using xanthate as an odorless sulfur source from easily acquirable 2′-halochalcones. This methodology demonstrates that the cross-coupled product thiochromanone synthesized from 2′-halochalcones (upstream reaction) is oxidized to thiochromenone (downstream reaction) in the same pot using waste byproduct (KI) of the first